Sunday, October 20, 2019

Chemtrails: A Little Truth Goes a Long Way

Proof of chemtrail's existence [Source: the internet]

Running a modest (~3600 follower) aviation themed Facebook page for the past four years has been quite an education in human online behavior. I have a following of fellow professional aviators, air traffic controllers, aviation industry employees and general lovers of aviation. Most everyone abides by the unwritten laws of "netiquette" but there are of course always a few of the usual characters who don't play well with others.

Pedants will pick out a minor mistake or unimportant nuance to trumpet superiority. Last worders must always finish any argument, and reading comprehension aficionados will repeat your point back to you as if it was their idea. Sometimes just not responding to a provocative comment will make the person doing the commenting explode. I don't use the ban hammer often but rather try to talk excitable respondents down off the ledge. But occasionally I get a live conspiracy theorist to happen by. These guys are the most fun of all.

Pick Your Conspiracy

There are many flavors of conspiracies out there from 9/11 "truthers" to flat Earthers to the ur-conspiracy surrounding the Kennedy assassination. Rather than the dissipation of pockets of unknowing as you might expect now that we have the sum total of human science and discovery in our phones, access to the internet only seems to have injected steroids into many conspiracy theories. Confirmation bias kicks into overdrive as whole communities spring up around crazy ideas.

Joseph Pierre, a psychiatrist writing in Psychology Today, makes the point that conspiracy believers venture from a healthy scientific skepticism into nihilistic denialism. Any and all facts are subject to question regardless of any evidence, no matter how convincing, as a matter of principle. I suppose there's an attraction to walking around believing that you have secret knowledge to which few others are privy.


In aviation circles, the conspiracy of choice is known as the "chemtrail" conspiracy. A portmanteau of chemical and contrails, itself a combination of "condensation trails", the chemtrail conspiracy posits that the lines in the sky which originate behind high flying aircraft are not condensation from the moisture in aircraft exhaust, but actually a chemical spray of nefarious origin designed for a sinister end.

These chemicals can be either psychotropic substances which are designed to keep a restive population compliant, or a melange of metallic particles which are used to control the weather or "geoengineer" the planetary climate by blocking solar radiation. This particular conspiracy dates back to the late 90s and appears to have been sparked by a military research paper speculating about a future method of warfare that might include chemical dispersion from aircraft.

A Kernel of Truth

The use of aircraft to spray chemicals, usually fertilizers and pesticides, has a history dating back to the 1920s. The first aerial application of agricultural chemicals took place in 1921 from McCook Field in Dayton, Ohio. More recently, the US military undertook a large scale defoliation effort from 1962 to 1971 during the Vietnam conflict. Dubbed Operation Ranch Hand, Air Force C-123 Provider aircraft dispensed an estimated total of 20 million gallons of herbicides over Vietnam jungles.

Given this history, it isn't too great of a jump for the conspiracy minded to believe that the government has just upped their game and is now using commercial aircraft to poison the population or control the climate. Adherents will often conflate high altitude contrails which are a product of jet exhaust with low altitude wing top mist generation which is a result of the generation of lift in high humidity environments. Entire websites complete with well produced video content exist to promulgate chemtrail theories.

My Very Own Conspiracist

As I'd had thoughts about addressing this subject for awhile, I had the good fortune to have a true believer find his way onto my page. Let's call him Rob (name changed). Rob started out sending me private messages asking how it was that an attitude indicator (artificial horizon) could stay erect to the horizon if an aircraft is actually travelling over a globe.

It's actually a fair question and a real issue. He was unknowingly describing an actual phenomenon called "Earth rate" or "Earth transport" precession. An uncorrected gyro actually would slowly become inaccurate if it stayed true to its starting location as an aircraft travelled the globe. Both of these effects are accounted and corrected for in modern flight management computers. 

This explanation was answered by an angry response that he'd taken an attitude indicator apart and saw no such correction mechanism. This was probably true in that general aviation aircraft don't need such mechanisms due to their high cost and short range. A link to a Wikipedia article was met with a scoff. I didn't really expect him to believe in anything from Wikipedia, did I? How stupid did I think he was after all?

The conversation continued in this fashion. He'd ask why an aircraft travelling in a straight line over a globe wouldn't simply leave the atmosphere as if on a tangent line. The reply that aircraft don't fly in straight lines but use barometric pressure to maintain altitude in the atmosphere which is curved over the planet was also scoffed at. I hadn't "proved" anything.

It then occurred to me that he was a flat Earth believer. Rather than chase him off, I asked how he had come to his views. He mentioned that a ride in a helicopter some years past had provided him with his epiphany. He never did say exactly how that ride convinced him of the flatness of the Earth though. 

I then asked for some reference material. A trove of internet memes and links to videos followed. These memes would show things like graphic representations of an aircraft flying off into space on a straight line course, or a picture of drain or fuel dump vents on airliners as proof of the conspiracy.

Concerning chemtrails, he eventually conceded that rather than a conscious conspiracy of many thousands of commercial pilots and aircraft mechanics, the chemtrail chemicals might actually be added into the fuel directly, thereby limiting the conspiracy to fuel handlers and refiners.

The Pendulum

Looking for a simple way to demonstrate the Earth was not flat which would not rely on technology which he mistrusted, I recalled seeing a heavy four story pendulum hung in a stairwell in the Franklin Institute science museum in Philadelphia. Every morning employees would set up a circle of chess pieces under the pendulum and set it swinging. The pendulum would  knock down the chess pieces as the day progressed thereby demonstrating the rotation of the Earth. There was no way to ignore that!

The answer came back that Franklin was a Freemason and, well, nothing that he touched could be trusted. Interestingly, that was followed by several videos showing Masonic iconography which depicts the sun the same size as the moon with a flat horizon in the background, so it was difficult to know whether the Masons were with him or against him. What was clear was that a thread of mystical religiosity informed his world view and he was not going to let anyone pop the bubble.

What was also clear was that he wasn't going to attempt to address any incongruities that I raised such as how I could video call my wife from China where it was clearly dark at noon. This was just fascinating to me. I clearly didn't want to know the "truth" of his "research" which consisted of internet memes and videos posted by like-minded conspiracists.

Is It Harmless?

By all accounts my interlocutor seemed like a nice guy who got on well enough in society to hold a job and function normally. He mentioned that his job involved some sort of mechanical proficiency, and he did spend quite a bit of time on Facebook, so he wasn't obviously a technophobe. I even admired his inquisitiveness about the world. 

He was thinking about things that many people never consider, but at some point he wouldn't make the leap to the rational conclusion. Many of his positions started with a bit of truth which was then extrapolated to fantasy. The Psychology Today article referenced above noted that a confusion of the notions of  "believe in" versus "believe that" might be part of the cause of these belief systems.

I can't say that walking around believing in a flat Earth or chemtrails is an unalloyed tragedy. If it works for him, then great. In the words of that great 20th century philosopher, John Lennon: "Whatever gets you through the night is alright."

In Conclusion

One of the attributes which is emblematic of all conspiracies is that they're unfalsifiable. Any time an explanation is offered, there will be a counter-explanation which can't be verified. One of the best depictions of this was the scene from the first Terminator movie where Michael Biehn tries to explain to an incredulous prison doctor how robots from the future are coming to kill Sarah Connor.

Of course the joke here is that there actually were robots coming from the future to commit mayhem. But then, it was only a movie. Or was it?

Sunday, October 13, 2019

Did Bad Grammar Doom the Max?

emergency checklist to be used for a runaway stabilizer trim malfunction

As of this writing, the 737 MAX remains grounded with projected return dates now stretching into the first quarter of 2020. Boeing has not as of yet submitted the software fix for the controversial MCAS system to the FAA for evaluation. The European Aviation Safety Agency (EASA) recently indicated that they will seek their own additional testing of the software fix possibly resulting in a staggered return of the aircraft to service.

The post-mortem examinations of what went wrong at Boeing and the assumptions that were made concerning the flawed MCAS software continue. At issue is one assumption made early on that any malfunction in the MCAS system would be immediately recognized by average pilots as a malfunction known as "runaway stabilizer" for which a checklist already exists.

The stabilizer trim system is used by the pilots or the autopilot to keep the horizontal stabilizer in "trim" which means keeping the stabilizer aligned with the slipstream of air. It does this by actually moving the entire stabilizer a through a range of angles which change with airspeed. An "out of trim" stabilizer means the stabilizer is not perfectly aligned with the passing wind. This results in the need to hold force on the control column to maintain altitude. Letting go of the controls in such a condition would result in an undesired climb or descent. A well trimmed aircraft will stay where you put it.

In the 737, the stabilizer trim is normally controlled electrically through a motor, but can also be adjusted manually through a wheel and handle on the center stand. This system has a failure mode known as "runaway trim" wherein the motor runs after the control column electric trim switch has been released most likely due to a sticky or failed switch. This malfunction can result in an unflyable condition if not quickly corrected. It is this failure mode which is addressed by the "runaway stabilizer" checklist reproduced above.

Continuously or Continually?

Boeing engineers were also counting on pilots using this same runaway stabilizer checklist in the event that the MCAS system, which also uses the stabilizer trim, malfunctioned. The problem with this assumption is that the two malfunctions can appear to be very different things. During a classic stuck switch runaway trim, the trim wheel in the cockpit starts spinning and does not stop. That's the definition of "continuously" and is correctly annotated as one of the conditions on the top of the checklist.

An MCAS malfunction, however, presented quite differently. During that malfunction, the MCAS system would spin the trim wheel forward for a specified amount and then stop. If the pilot then used the trim switches to adjust the trim in a nose up direction, a malfunctioning MCAS would wait five seconds and trim forward again after each input by the pilot. This "very often; at regular or frequent intervals"  behavior of the MCAS system is the definition of "continually", not "continuously". 

This is exactly what happened to Lion 610. After reversing the MCAS inputs multiple times, the captain passed control of the aircraft to his first officer who was apparently unaware of the inputs the captain had been making. He never countered the next MCAS input which doomed them.

From Dictionary [dot] com:

In formal contexts, continually should be used to mean “very often; at regular or frequent intervals,” and continuously to mean “unceasingly; constantly; without interruption.”

Is this a minor and pedantic point? Perhaps, but perhaps not. English is the international language of aviation, and all pilots are expected to be proficient in English to be qualified to fly in international airspace. The pilots of both Lion 610 and Ethiopian 302 were likely not native English speakers and were highly unlikely to be aware of such a nuance as the difference in meaning of these two words.

They were, however trained in the various failure modes of their aircraft, and were not likely to be expecting the intermittent behavior of the failed MCAS system. The pilots of Lion 610 had no knowledge of the existence of the MCAS system as it was not included in their flight manuals. The pilots of Ethiopian 302 did have the Emergency Airworthiness Directive (EAD) published by Boeing describing the MCAS system, but were still slow to recognize that their problem originated from a bad MCAS system until too late.

In Conclusion

Aircraft flight manuals should contain all the information needed by pilots to safely operate their aircraft. This information should include accurate descriptions of possible failures, the recognizance of such failures, and best practices on how to solve or mitigate problems that arise. The omission of the existence and description of MCAS from the MAX airplane flight manual only compounded the problems faced by the two mishap aircrews. Faced with a fusillade of warnings and distractions which served to conceal the real nature of their problem, they were defenseless against a poorly designed and undocumented but deadly adversary.